1. Field of the Invention
This invention relates to an earthquake alarm assembly capable of being self-contained by including a DC battery source and a circuit means which allows the activation and closing of at least one of a plurality of switches causing current feed to an audible indicator structure when displacement of an activating member occurs due to earth tremors effecting the stability of a building structure.
2. Description of the Prior Art
In certain geographical locations in the world natural phenomenon known as earthquakes are quite common. When such naturally inclined earthquake areas are also the location of large population sites, property damage and loss of life and injury are a factor to be reckoned with in everyday life.
While earth tremors associated with earthquakes are obviously self-evident during most of the day, as when people are awake, at work, etc. there is a particular danger of the aforementioned damage being done during the evening hours when most of the members of a population are asleep.
Accordingly, there is a need in the alarm industry for an alarm device specifically designed to warn sleeping occupants in a dwelling structure and like location that earth tremors have begun. Typically, major earthquakes begin with somewhat minor earth tremor disturbances which are not readily detected by those who are sleeping. However, it is also generally acknowledged that early detection and warning of an oncoming earthquake and the more serious earth tremors associated therewith is necessary to avoid bodily harm to the extent of remaining within the open areas of buildings without taking necessary precautions. The existence and automatic activation and operation of an earthquake alarm would be desirable therefore from the standpoint of awaking sleeping occupants of a building even during the onset of minor earth tremors. In such a preferred embodiment an audible indicator or signal could be activated of sufficient intensity to wake up people throughout a single family dwelling structure or the larger structures such as in hotels, dormitories, etc.
The prior art has attempted numerous structures, indicators, alarms, etc. in an effort to provide a selection of devices which solve the above set forth problem. Such devices are disclosed in the following U.S. patents which include: U.S. Pat. Nos. 4,028,659; 4,028,567; 4,107,545; 4,361,740 and 4,470,040. Particularly, in the last indicated patent, the structure disclosed therein relates to a microvibration detector using a single peizoelectric element as both sensor and alarm generator. In the device disclosed therein and being representative of prior art devices, a sound emitter receives a vibration and in turn generates an electromotive force that causes activation of an alarm. However, in the specification of this patent, the inventor indicates that his invention operates by contact. When a person steps on a thin plate causing the alarm to generate. While alarms of this type are generally well known they are not adaptable for an earthquake alarm.